WO2007080247A1 - Secondary filtration device applicable to a three-phase process - Google Patents

Secondary filtration device applicable to a three-phase process Download PDF

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Publication number
WO2007080247A1
WO2007080247A1 PCT/FR2006/002648 FR2006002648W WO2007080247A1 WO 2007080247 A1 WO2007080247 A1 WO 2007080247A1 FR 2006002648 W FR2006002648 W FR 2006002648W WO 2007080247 A1 WO2007080247 A1 WO 2007080247A1
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WO
WIPO (PCT)
Prior art keywords
particles
layers
microns
layer
secondary separation
Prior art date
Application number
PCT/FR2006/002648
Other languages
French (fr)
Inventor
Matthieu Rolland
Nathalie Brunard
Jean-Christophe Viguie
Original Assignee
Institut Francais Du Petrole
Eni S.P.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institut Francais Du Petrole, Eni S.P.A. filed Critical Institut Francais Du Petrole
Priority to CN2006800480873A priority Critical patent/CN101410161B/en
Priority to DE602006009558T priority patent/DE602006009558D1/en
Priority to PL06841856T priority patent/PL1965885T3/en
Priority to EP06841856A priority patent/EP1965885B1/en
Priority to AT06841856T priority patent/ATE444113T1/en
Priority to US12/158,428 priority patent/US8092694B2/en
Publication of WO2007080247A1 publication Critical patent/WO2007080247A1/en
Priority to NO20082392A priority patent/NO344338B1/en
Priority to EG2008050890A priority patent/EG25597A/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/007—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with multiple filtering elements in series connection
    • B01D24/008—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with multiple filtering elements in series connection arranged concentrically or coaxially
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/02—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration
    • B01D24/10—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being held in a closed container
    • B01D24/105—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being held in a closed container downward filtration without specifications about the filter material supporting means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D24/00—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof
    • B01D24/02—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration
    • B01D24/10—Filters comprising loose filtering material, i.e. filtering material without any binder between the individual particles or fibres thereof with the filter bed stationary during the filtration the filtering material being held in a closed container
    • B01D24/16—Upward filtration
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G2/00—Production of liquid hydrocarbon mixtures of undefined composition from oxides of carbon
    • C10G2/30—Production of liquid hydrocarbon mixtures of undefined composition from oxides of carbon from carbon monoxide with hydrogen
    • C10G2/32—Production of liquid hydrocarbon mixtures of undefined composition from oxides of carbon from carbon monoxide with hydrogen with the use of catalysts
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G31/00—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for
    • C10G31/09—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for by filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2201/00—Details relating to filtering apparatus
    • B01D2201/18—Filters characterised by the openings or pores
    • B01D2201/188—Multiple filtering elements having filtering areas of different size

Definitions

  • the present invention describes a device for the secondary filtration of the catalyst particles contained in a process effluent comprising a reactor operated in three-phase mode, that is to say with a solid suspended in a liquid phase and in the presence of a gas phase.
  • said solid is a catalyst for the reaction and the liquid and / or the solid are reagents.
  • the liquid or solid may also be inert in said reaction.
  • the present invention also relates to the separation process using said device.
  • the present invention thus relates for example to the case of a Fischer-Tropsch process, which makes it possible to synthesize a very wide range of hydrocarbons from a mixture of carbon monoxide and hydrogen, known as synthesis.
  • This process known since the 1930s, has been extensively described and here we will summarize the essential characteristics of its implementation in a "slurry" type reactor.
  • a "slurry" reactor is a three-phase reactor in which the catalyst particles in suspension in a liquid phase are very finely divided, typically with an average size of the order of 5 microns to 700 microns, and are therefore substantially integral with the phase. liquid containing them, said liquid phase itself being traversed by a flow of gas bubbles of very large size.
  • the complex hydrodynamic system consisting of solid particles of catalyst suspended in a hydrocarbon liquid phase traversed by gas bubbles comprising hydrogen and carbon monoxide constitutes the medium called by the skilled person "slurry", in the context of the Fischer-Tropsch process. This term is also used in other fields and in particular for other processes operated in the presence of a liquid phase and a gas phase.
  • the term "slurry” is therefore used in the rest of the text with the definition given above.
  • An example of a "slurry” reactor is, for example, a perfectly stirred autoclave comprising a catalyst in suspension.
  • Another example of a "slurry” reactor is a reactor comprising a catalyst suspended in a liquid phase known as a bubble column or "slurry bubble column” (SBC) according to English terminology.
  • SBC slurry bubble column
  • the gas is admitted, generally at the bottom of the reactor, into a vertical reactor several meters in diameter and high (typically several tens of meters for an industrial reactor) comprising a liquid phase with a catalyst in
  • the separation of the solid catalyst particles from the suspension is an important aspect of the three-phase processes and more particularly of the Fischer-Tropsch process, because it partly conditions the feasibility and economy of the process.
  • the device and the separation method which are the subject of the present invention, apply in particular to the separation of the catalyst particles in a three-phase process, for example a Fischer-Tropsch process implemented in "slurry".
  • This device and this method may also relate to any separation of solid particles with a diameter of preferably less than 50 microns, and more preferably less than 20 microns, in suspension in any hydrocarbon medium.
  • the patent application US 2005/0004414 A1 describes the elimination of ultrafine particles capable of clogging the reactor, the device comprising a primary filtration not described, and a secondary catalytic filtration using a catalyst comprising at least one metal belonging to groups VI or VIII deposited on a silica alumina support.
  • the cited document describes a mechanism for "desolubilization" ultrafine particles that precipitate in the pores of the particles constituting the catalytic filter.
  • the present invention differs from the catalytic mechanism described in the cited document since it is based on the formation of a cake on a first filter media, followed by a deep trapping inside a second filter media.
  • the patent application WO 2005/005038 A1 describes a filtration through a filtration medium having openings of size between 10 and 25 microns with formation of a cake which is periodically retrolaved, generally at the same time as the backwash of the In the present invention, there is no backwashing of the filter medium, and the filter system once saturated is replaced by a new system.
  • backwashing in the context of the patent cited means a reverse flow of the process fluid, for driving the particles deposited on the filter media.
  • Patent Applications US 2005/0000861 A1 and US 2004/0266894 A1 describe a Fischer-Tropsch "slurry" process provided with a solid particle separation system comprising a primary filtration on cartridge, which can be located inside. or outside the reactor, and a secondary filtration called micro or ultra filtration, using a very fine porous material whose pore size is between 0.002 and 0.1 micron.
  • the secondary filtration system is connected to the primary filtration system to form a single coaxial assembly.
  • the secondary filtration system is independent of the primary filtration system, and is located outside the reactor.
  • the secondary filtration system according to the invention consists of a granular bed comprising at least two distinct layers.
  • FIG. 1 is an overview of the Fischer-Tropsch process operating in "slurry" mode showing the location of the primary separation system and the secondary separation system according to the invention.
  • FIG. 2 represents a view of an axial secondary filtration bed according to the invention with its different layers.
  • FIG. 3 represents a view of a radial secondary filtration bed according to the invention with its different layers.
  • the present invention consists of a secondary filtration device applicable in particular to a Fischer-Tropsch hydrocarbon synthesis process using a "slurry" type reactor.
  • the separation device according to the present invention is called secondary in that it follows a primary separation device which makes it possible to remove solid particles of catalyst with a diameter greater than about 20 microns.
  • the primary separation device is not the subject of the present invention, but such a device is in particular described in the patent application US 2005/0000861 A1.
  • Any primary separation device for removing the fraction of solid particles having a particle size greater than 50 microns, and preferably greater than 20 microns, is compatible with the secondary separation device object of the present invention. It may be in particular a primary separation device by decantation or by filtration.
  • the present secondary separation device consists essentially of a granular bed comprising at least two layers:
  • a first storage layer consisting of inert macroporous particles having a diameter of between 1 and 3 mm, preferably between 1.5 and 2.5 mm,
  • a second layer consisting of inert particles having a size distribution between 0.4 micron and 80 microns, with a mean diameter of between 25 microns and 35 microns.
  • the storage layer of the device according to the invention generally has a mean porosity of between 60% and 75%, and preferably between 65% and 70%.
  • the storage layer of the device according to the invention will generally have a specific surface area of between 100 and 200 m 2 / gram, and preferably between 150 and 180 m 2 / gram.
  • the storage layer may be single or composed of multiple layers having particle size, porosity and specific surface specifications within the limits indicated.
  • the total thickness of the storage layer or layers is between 0.3 meters and 2 meters, and preferably between 0.5 meters and 1 meter.
  • the deep filtration layer has a particle size distribution such that 5% to 20% of the volume of the layer is represented by particles smaller than 4 microns in diameter.
  • the deep filtration layer of the device according to the invention generally has a void fraction of between 0.2 and 0.45 (that is to say between 20% and 45% by volume) and preferably between 0.25 and 0.25. and 0.4.
  • the deep filtration layer may be single or composed of several layers meeting particle size and particle size distribution specifications within the limits indicated, a percentage of the fraction less than 4 microns which should preferably represent between 5% and 20% of the volume of the deep filtration layer or layers.
  • the total thickness of the deep filtration layer or layers is between 0.1 meter and 2 meters, and preferably between 0.2 meters and 1.5 meters.
  • the secondary separation device according to the invention may have two modes of operation:
  • the layers are in the form of concentric rings traversed laterally from the periphery towards the center or from the center towards the periphery, the storage layer or layers being always traversed before the deep filtration layer or layers.
  • the present invention is in the context of a process for the synthesis of hydrocarbons from a gaseous mixture comprising carbon monoxide and hydrogen, generally called synthesis gas, in a "slurry" type reactor in the previously defined sense. It may nevertheless apply more generally to any separation of solid particles with a diameter of less than 50 microns, and preferably less than 20 microns, said particles being suspended in a hydrocarbon liquid phase.
  • the initial particle size of said catalyst can evolve by attrition and the percentage of fine particles then tends to increase over time.
  • Fischer-Tropsch catalysts typically comprise cobalt or iron distributed on a support based on at least one of the following metal oxides or mixtures thereof: silicon (Si), titanium (Ti), aluminum (Al), zirconium ( Zr) or magnesium (Mg).
  • the fluidized reactor (A) operates in "slurry", with an internal exchanger comprising one or more cooling loops (3) supplied by a fluid (liquid or vapor) cooling.
  • the gaseous feed is introduced into the reactor by means of the distributor noted (B) and the line (1).
  • a liquid recirculation loop containing a portion of gas is extracted at an upper point of the reactor by the line (2) and feeds a degasser noted (C).
  • the gas is removed via the line (5) and the liquid phase is extracted from the degasser (C) by the line (6), then introduced into the primary separation system (E).
  • a first liquid fraction (7) fed to the "slurry" reactor is extracted via the pump (D) and the line (8), and a second liquid fraction (9). ) which feeds the secondary filtration device (F).
  • By the line (10) is collected a liquid product meeting the specifications of solid content.
  • the "slurry" reactor comprises a primary separation system (E) for the catalyst particles, which is not described in the present application, but which is preferably either of decanter type or a system of filter cartridges.
  • This primary separation system may be either external to the reactor, as indicated in FIG. 1, or internal to said reactor (not shown).
  • the device for separating the solid particles is completed by a secondary filtration (F), object of the present invention, which makes it possible to lower the concentration of particles in the effluents of the reactor to less than 10 ppm (parts per million), and preferentially less than 5 ppm.
  • F secondary filtration
  • the solid particles to be separated in the secondary filtration system are fine catalyst particles, whose diameter is generally less than 50 microns, and most often, depending on the performance of the primary separation, less than 20 microns. These particles may include ultrafine particles smaller than one micron (also called submicron particles).
  • the concentration of fine particles at the inlet of the secondary filtration system is generally between 50 and 500 ppm.
  • the secondary separation device essentially consists of a bed comprising at least two distinct particle layers, a first layer intended to facilitate the formation of a cake, also called a storage layer, and a second layer intended to trap in depth the fine particles of catalyst, also called deep filtration layer.
  • FIG. 2 shows a secondary filtration device according to the invention, operating in axial mode and fed by the liquid charged with particles by the line (6), the liquid deconcentrated in particles being evacuated via the line (7).
  • the secondary filtration device comprises at least one guard layer (1), at least one storage layer (2), at least one deep filtration layer (3), and at least one protective layer (4) and (5) ).
  • the first layer, or storage layer (2) generally consists of inert macroporous particles with a diameter of between 1 and 3 mm, preferably between 1.5 and 2.5 mm.
  • the average porosity of the storage layer is generally between 60% and 75%, and preferably between 65% and 70% by volume.
  • the porous surface offered by the storage layer will generally be between 100 and 200 m 2 / gram, and preferably between 150 and 180 m 2 / gram.
  • the second or deep filtration layer (3) consists of inert particles having a size distribution of between 0.4 and 80 microns, with an average diameter of between 25 and 35 microns.
  • Said deep filtration layer has a particle size distribution such that 5% to 20% of the volume of the layer is represented by particles smaller than 4 microns in diameter.
  • the porous surface offered by the deep filtration layer is generally between 100 and 400 m 2 / gram, and preferably between 200 and 300 m 2 / gram.
  • the initial void ratio of the deep filtration layer is generally between 0.20 and 0.45, and preferably between 0.25 and 0.4. During filtration, this void rate decreases due to the solid particles settling inside the deep filtration layer, causing an increase in the pressure loss at the crossing of the device.
  • the secondary filtration bed is generally operated at a temperature of between 130 ° C. and 250 ° C., and preferably between 150 ° C. and 23 ° C.
  • the superficial velocity of the fluid charged in fine particles inside the filtration bed is generally between 0.3 meters / hour and 1 meter / hour.
  • the superficial velocity is defined as the ratio of the volume flow rate of charge to the empty section of the filtration bed.
  • the thickness of the storage layer is preferably between 0.3 meters and 2 meters, and more preferably between 0.5 meters and 1.0 meters.
  • the thickness of the deep filtration layer is preferably between 0.1 meters and 2 meters, and preferably between 0.2 meters and 1.5 meters.
  • the filtration device according to the invention may optionally contain several storage layers and several deep filtration layers, a storage layer preferably having at least a thickness of 0.3 meters, and a deep filtration layer preferably having at least a thickness of 0.1 meters.
  • the thickness limit of the secondary filtration bed is conditioned by the pressure loss, which must remain below a limit value depending on the power of the pumps installed.
  • the pressure loss is maintained at 0.1 MPa, preferably at 0.05 MPa at the end of filtration.
  • the loss of pressure increases with retention in fine particles.
  • the filter is stopped to be emptied either by gravity or by suction from above. All layers must be replaced before restarting the filter.
  • One of the advantages of the invention is that, if the charge evolves, and with it the characteristics of the particles to be filtered, it is very easy to modulate the thicknesses and / or the type of filtration media used to optimize filtration under the new conditions.
  • the typical operating time of the secondary filtration system according to the invention is at least 5 days, and preferably at least 10 days.
  • the Fischer-Tropsch synthesis unit in which the secondary filtration device according to the invention is incorporated comprises a slurry reactor of the SBC type (bubble column with a suspension catalyst or "Slurry Bubble Column", according to the anglosaxon terminology) treating 30 tonnes / hour of a syngas charge under the following operating conditions:
  • the catalyst used is based on cobalt, and the particles in suspension have an average diameter of 150 microns, 300 ppm of which have a diameter of less than 25 microns.
  • the primary filtration system consists of a set of filtration cartridges of commercial type PALL type "Rigimesh K".
  • Example 1 (according to the invention, FIG. 2)
  • the secondary filtration device In axial mode, the secondary filtration device consists of 4 parallel filtration beds, one of which is disconnected to allow unloading. Each filter bed has a diameter of 5.3 meters, and has the following 6 layers from top to bottom:
  • the cycle time of a bed that is to say its operating time before disconnection is 63 days.
  • the content of particles at the outlet of the secondary filtration is less than 5 ppm and the effluent is totally white.
  • Example 2 (according to the invention, FIG. 3)
  • the secondary filtration device In radial mode, the secondary filtration device consists of two radial beds, one of which is in an unloading situation. Each radial bed is composed of coaxial cylindrical layers. The outside diameter of a bed is 6.4 meters and its total height is 8.7 meters.
  • a deep filtration layer (3) 1.2 meters thick, consisting of alumina particles with a diameter of between 20 and 30 microns of GA.3001 type,
  • a guard layer (4) composed of particles of diameter between 60 and 500 microns
  • the operating time of a bed is 62 days.
  • the content of particles at the outlet of the secondary filtration is less than 5 ppm and the effluent is totally white.
  • the particles in a very small quantity still present in the filtration effluent secondary have a diameter less than 0.2 micron, so that the liquid effluent after cooling, consisting essentially of paraffins, is completely white. However, as soon as the effluent contains at least 10 ppm of particles, it usually becomes gray. The visual test is therefore perfectly discriminating and confirms the low particulate content of the effluent.

Abstract

The present invention describes a device allowing secondary filtration of catalyst particles contained in a process effluent comprising a reactor operated in three-phase mode.

Description

DISPOSITIF DE FILTRATION SECONDAIRE APPLICABLE A UN PROCEDE TRIPHASIQUESECONDARY FILTRATION DEVICE APPLICABLE TO A THREE PHASE PROCESS
DOMAINE DE L'INVENTIONFIELD OF THE INVENTION
La présente invention décrit un dispositif permettant la filtration secondaire des particules de catalyseur contenues dans un effluent de procédé comprenant un réacteur opéré en mode triphasique, c'est-à-dire avec un solide en suspension dans une phase liquide et en présence d'une phase gazeuse. Le plus souvent, ledit solide est un catalyseur de la réaction et le liquide et/ou le solide sont des réactifs. Le liquide ou le solide peuvent également être inertes dans ladite réaction.The present invention describes a device for the secondary filtration of the catalyst particles contained in a process effluent comprising a reactor operated in three-phase mode, that is to say with a solid suspended in a liquid phase and in the presence of a gas phase. Most often, said solid is a catalyst for the reaction and the liquid and / or the solid are reagents. The liquid or solid may also be inert in said reaction.
La présente invention concerne également le procédé de séparation mettant en oeuvre ledit dispositif.The present invention also relates to the separation process using said device.
La présente invention concerne ainsi par exemple le cas d'un procédé Fischer-Tropsch, qui permet de réaliser la synthèse d'une gamme très large d'hydrocarbures à partir d'un mélange de monoxyde de carbone et d'hydrogène, appelé gaz de synthèse. Ce procédé connu depuis les années 1930, a été abondamment décrit et nous résumerons ici les caractéristiques essentielles de sa mise en oeuvre dans un réacteur de type "slurry".The present invention thus relates for example to the case of a Fischer-Tropsch process, which makes it possible to synthesize a very wide range of hydrocarbons from a mixture of carbon monoxide and hydrogen, known as synthesis. This process, known since the 1930s, has been extensively described and here we will summarize the essential characteristics of its implementation in a "slurry" type reactor.
Un réacteur "slurry" est un réacteur triphasique dans lequel les particules de catalyseur en suspension dans une phase liquide sont très finement divisées, typiquement avec une taille moyenne de l'ordre de 5 microns à 700 microns, et sont donc pratiquement solidaires de la phase liquide qui les contient, ladite phase liquide étant elle-même traversée par un flux de bulles de gaz de taille très étalée.A "slurry" reactor is a three-phase reactor in which the catalyst particles in suspension in a liquid phase are very finely divided, typically with an average size of the order of 5 microns to 700 microns, and are therefore substantially integral with the phase. liquid containing them, said liquid phase itself being traversed by a flow of gas bubbles of very large size.
Le système hydrodynamique complexe constitué des particules solides de catalyseur en suspension dans une phase liquide hydrocarbure traversée par des bulles de gaz comprenant de l'hydrogène et du monoxyde de carbone, constitue le milieu appelé par l'homme du métier "slurry", dans le contexte du procédé Fischer-Tropsch. Ce terme est également utilisé dans d'autres domaines et notamment pour d'autres procédés opérés en présence d'une phase liquide et d'une phase gazeuse. Le terme "slurry" est donc employé dans la suite du texte avec la définition donnée ci- dessus. Un exemple de réacteur "slurry" est par exemple un autoclave parfaitement agité comprenant un catalyseur en suspension. Un autre exemple de réacteur "slurry" est un réacteur comprenant un catalyseur en suspension dans une phase liquide connu sous le nom de colonne à bulles ou "slurry bubble column" (SBC) selon la terminologie anglosaxonne. Dans un réacteur S B C, le gaz est admis, généralement en bas du réacteur, dans un réacteur vertical de plusieurs mètres de diamètre et de grande hauteur (typiquement plusieurs dizaines de mètres pour un réacteur industriel) comprenant une phase liquide avec un catalyseur en suspension.The complex hydrodynamic system consisting of solid particles of catalyst suspended in a hydrocarbon liquid phase traversed by gas bubbles comprising hydrogen and carbon monoxide constitutes the medium called by the skilled person "slurry", in the context of the Fischer-Tropsch process. This term is also used in other fields and in particular for other processes operated in the presence of a liquid phase and a gas phase. The term "slurry" is therefore used in the rest of the text with the definition given above. An example of a "slurry" reactor is, for example, a perfectly stirred autoclave comprising a catalyst in suspension. Another example of a "slurry" reactor is a reactor comprising a catalyst suspended in a liquid phase known as a bubble column or "slurry bubble column" (SBC) according to English terminology. In an SBC reactor, the gas is admitted, generally at the bottom of the reactor, into a vertical reactor several meters in diameter and high (typically several tens of meters for an industrial reactor) comprising a liquid phase with a catalyst in suspension.
La séparation des particules solides de catalyseur de la suspension est un aspect important des procédés triphasiques et plus particulièrement du procédé Fischer-Tropsch, car il conditionne en partie la faisabilité et l'économie du procédé.The separation of the solid catalyst particles from the suspension is an important aspect of the three-phase processes and more particularly of the Fischer-Tropsch process, because it partly conditions the feasibility and economy of the process.
Le dispositif et le procédé de séparation, objets de la présente invention, s'appliquent en particulier à la séparation des particules de catalyseur dans un procédé triphasique, par exemple un procédé Fischer-Tropsch mis en oeuvre en "slurry". Ce dispositif et ce procédé, peuvent également concerner toute séparation de particules solides de diamètre de préférence inférieur à 50 microns, et plus préférentiellement inférieur à 20 microns, en suspension dans un milieu hydrocarbure quelconque.The device and the separation method, which are the subject of the present invention, apply in particular to the separation of the catalyst particles in a three-phase process, for example a Fischer-Tropsch process implemented in "slurry". This device and this method may also relate to any separation of solid particles with a diameter of preferably less than 50 microns, and more preferably less than 20 microns, in suspension in any hydrocarbon medium.
EXAMEN DE L'ART ANTERIEUREXAMINATION OF THE PRIOR ART
La demande de brevet US 2005/0004414 A1 décrit l'élimination de particules ultrafines susceptibles de boucher le réacteur, le dispositif comportant une filtration primaire non décrite, et une filtration secondaire catalytique utilisant un catalyseur comprenant au moins un métal appartenant aux groupes Vl ou VIII déposé sur un support de silice alumine. Le document cité décrit un mécanisme de "désolubilisation" des particules ultrafines qui précipitent dans les pores des particules constituant le filtre catalytique.The patent application US 2005/0004414 A1 describes the elimination of ultrafine particles capable of clogging the reactor, the device comprising a primary filtration not described, and a secondary catalytic filtration using a catalyst comprising at least one metal belonging to groups VI or VIII deposited on a silica alumina support. The cited document describes a mechanism for "desolubilization" ultrafine particles that precipitate in the pores of the particles constituting the catalytic filter.
La présente invention diffère du mécanisme catalytique décrit dans le document cité puisqu'elle repose sur la formation d'un gâteau sur un premier média filtrant, suivi d'un piégeage en profondeur à l'intérieur d'un second média filtrant. La demande de brevet WO 2005/005038 A1 décrit une filtration à travers un média de filtration présentant des ouvertures de taille comprise entre 10 et 25 microns avec formation d'un gâteau qui est périodiquement retrolavé, en général en même temps que le rétrolavage de la filtration primaire, Dans la présente invention, il n'y a pas de rétrolavage du média filtrant, et le système de filtration une fois saturé est remplacé par un système neuf. Le terme rétrolavage dans le contexte du brevet cité, signifie un passage à courant inverse du fluide procédé, permettant d'entraîner les particules déposées sur le média filtrant.The present invention differs from the catalytic mechanism described in the cited document since it is based on the formation of a cake on a first filter media, followed by a deep trapping inside a second filter media. The patent application WO 2005/005038 A1 describes a filtration through a filtration medium having openings of size between 10 and 25 microns with formation of a cake which is periodically retrolaved, generally at the same time as the backwash of the In the present invention, there is no backwashing of the filter medium, and the filter system once saturated is replaced by a new system. The term backwashing in the context of the patent cited, means a reverse flow of the process fluid, for driving the particles deposited on the filter media.
Les demandes de brevets US 2005/0000861 A1 et US 2004/0266894 A1 décrivent un procédé Fischer-Tropsch en "slurry" muni d'un système de séparation des particules solides comportant une filtration primaire sur cartouche, qui peut être située à l'intérieur ou à l'extérieur du réacteur, et une filtration secondaire appelée micro ou ultra filtration, faisant appel à un matériau poreux très fin dont la taille des pores est comprise entre 0,002 et 0,1 micron. Le système de filtration secondaire est connecté au système de filtration primaire pour former un ensemble coaxial unique.Patent Applications US 2005/0000861 A1 and US 2004/0266894 A1 describe a Fischer-Tropsch "slurry" process provided with a solid particle separation system comprising a primary filtration on cartridge, which can be located inside. or outside the reactor, and a secondary filtration called micro or ultra filtration, using a very fine porous material whose pore size is between 0.002 and 0.1 micron. The secondary filtration system is connected to the primary filtration system to form a single coaxial assembly.
Dans la présente invention, le système de filtration secondaire est indépendant du système de filtration primaire, et se situe à l'extérieur du réacteur. Comme il sera exposé en détail plus loin, le système de filtration secondaire selon l'invention est constitué d'un lit granulaire comportant au moins deux couches distinctes.In the present invention, the secondary filtration system is independent of the primary filtration system, and is located outside the reactor. As will be explained in detail below, the secondary filtration system according to the invention consists of a granular bed comprising at least two distinct layers.
DESCRIPTION SOMMAIRE DES FIGURESSUMMARY DESCRIPTION OF THE FIGURES
La figure 1 est une vue d'ensemble du procédé Fischer-Tropsch fonctionnant en mode "slurry" montrant l'emplacement du système de séparation primaire et du système de séparation secondaire selon l'invention.FIG. 1 is an overview of the Fischer-Tropsch process operating in "slurry" mode showing the location of the primary separation system and the secondary separation system according to the invention.
La figure 2 représente une vue d'un lit axial de filtration secondaire selon l'invention avec ses différentes couches.FIG. 2 represents a view of an axial secondary filtration bed according to the invention with its different layers.
La figure 3 représente une vue d'un lit radial de filtration secondaire selon l'invention avec ses différentes couches.FIG. 3 represents a view of a radial secondary filtration bed according to the invention with its different layers.
Les numéros ou les lettres définissant les différents éléments de l'invention sont repris dans la description détaillée.The numbers or letters defining the various elements of the invention are included in the detailed description.
DESCRIPTION SOMMAIRE DE L'INVENTIONSUMMARY DESCRIPTION OF THE INVENTION
La présente invention consiste en un dispositif de filtration secondaire applicable en particulier à un procédé de synthèse Fischer-Tropsch d'hydrocarbures faisant appel à un réacteur de type "slurry". Le dispositif de séparation selon la présente invention est appelé secondaire dans la mesure où il fait suite à un dispositif de séparation primaire qui permet d'éliminer les particules solides de catalyseur d'un diamètre supérieur à environ 20 microns. Le dispositif de séparation primaire ne fait pas l'objet de la présente invention, mais un tel dispositif se trouve en particulier décrit dans la demande de brevet US 2005/0000861 A1.The present invention consists of a secondary filtration device applicable in particular to a Fischer-Tropsch hydrocarbon synthesis process using a "slurry" type reactor. The separation device according to the present invention is called secondary in that it follows a primary separation device which makes it possible to remove solid particles of catalyst with a diameter greater than about 20 microns. The primary separation device is not the subject of the present invention, but such a device is in particular described in the patent application US 2005/0000861 A1.
Tout dispositif de séparation primaire permettant d'éliminer la fraction de particules solides ayant une taille de particules supérieure à 50 microns, et préférentiellement supérieure à 20 microns, est compatible avec le dispositif de séparation secondaire objet de la présente invention. Il peut s'agir en particulier d'un dispositif de séparation primaire par décantation ou par filtration.Any primary separation device for removing the fraction of solid particles having a particle size greater than 50 microns, and preferably greater than 20 microns, is compatible with the secondary separation device object of the present invention. It may be in particular a primary separation device by decantation or by filtration.
Le présent dispositif de séparation secondaire consiste essentiellement en un lit granulaire comportant au moins deux couches :The present secondary separation device consists essentially of a granular bed comprising at least two layers:
• une première couche, dite de stockage, constituée de particules macroporeuses inertes, de diamètre compris entre 1 et 3 mm, préférentiellement compris entre 1 ,5 et 2,5 mm,A first storage layer consisting of inert macroporous particles having a diameter of between 1 and 3 mm, preferably between 1.5 and 2.5 mm,
• une seconde couche, dite de filtration profonde, constituée de particules inertes présentant une distribution de taille comprise entre 0,4 micron et 80 microns, avec un diamètre moyen compris entre 25 microns et 35 microns.• A second layer, called deep filtration, consisting of inert particles having a size distribution between 0.4 micron and 80 microns, with a mean diameter of between 25 microns and 35 microns.
La couche de stockage du dispositif selon l'invention a généralement une porosité moyenne comprise entre 60 % et 75 %, et préférentiellement comprise entre 65 % et 70 %. La couche de stockage du dispositif selon l'invention aura généralement une surface spécifique comprise entre 100 et 200 m2/gramme, et préférentiellement comprise entre 150 et 180 m2/gramme. La couche de stockage peut être unique ou composée de plusieurs couches répondant à des spécifications de diamètre de particules, de porosité et de surface spécifique situées dans les limites indiquées. L'épaisseur totale de la ou des couches de stockage est comprise entre 0,3 mètre et 2 mètres, et préférentiellement comprise entre 0,5 mètre et 1 mètre.The storage layer of the device according to the invention generally has a mean porosity of between 60% and 75%, and preferably between 65% and 70%. The storage layer of the device according to the invention will generally have a specific surface area of between 100 and 200 m 2 / gram, and preferably between 150 and 180 m 2 / gram. The storage layer may be single or composed of multiple layers having particle size, porosity and specific surface specifications within the limits indicated. The total thickness of the storage layer or layers is between 0.3 meters and 2 meters, and preferably between 0.5 meters and 1 meter.
De manière préférée, la couche de filtration profonde présente une distribution de taille de particules telle que 5 % à 20 % du volume de la couche soit représenté par des particules de diamètre inférieur à 4 microns.Preferably, the deep filtration layer has a particle size distribution such that 5% to 20% of the volume of the layer is represented by particles smaller than 4 microns in diameter.
La couche de filtration profonde du dispositif selon l'invention présente généralement une fraction de vide comprise entre 0,2 et 0,45 (c'est-à-dire entre 20 % et 45 % en volume) et préférentiellement comprise entre 0,25 et 0,4. De la même manière que pour la couche de stockage, la couche de filtration profonde pourra être unique ou composée de plusieurs couches répondant à des spécifications de diamètre de particules et de distribution de taille de particules situées dans les limites indiquées, soit un pourcentage de la fraction inférieure à 4 microns qui devra représenter préférentiellement entre 5 % et 20 % du volume de la ou des couches de filtration profonde. L'épaisseur totale de la ou des couches de filtration profonde est comprise entre 0,1 mètre et 2 mètres, et préférentiellement comprise entre 0,2 mètre et 1,5 mètres.The deep filtration layer of the device according to the invention generally has a void fraction of between 0.2 and 0.45 (that is to say between 20% and 45% by volume) and preferably between 0.25 and 0.25. and 0.4. In the same manner as for the storage layer, the deep filtration layer may be single or composed of several layers meeting particle size and particle size distribution specifications within the limits indicated, a percentage of the fraction less than 4 microns which should preferably represent between 5% and 20% of the volume of the deep filtration layer or layers. The total thickness of the deep filtration layer or layers is between 0.1 meter and 2 meters, and preferably between 0.2 meters and 1.5 meters.
Le dispositif de séparation secondaire selon l'invention pourra avoir deux modes de fonctionnement :The secondary separation device according to the invention may have two modes of operation:
- un mode axial dans lequel le fluide chargé en particules traverse le dispositif de haut en bas ou de bas en haut selon la disposition des couches, la ou les couches de stockage étant toujours traversées avant la ou les couches de filtration profonde,an axial mode in which the fluid loaded with particles passes through the device from top to bottom or from bottom to top depending on the arrangement of the layers, the storage layer or layers being always traversed before the deep filtration layer or layers,
- un mode radial dans lequel les couches se présentent sous forme d'anneaux concentriques traversés latéralement de la périphérie vers le centre ou du centre vers la périphérie, la ou les couches de stockage étant toujours traversées avant la ou les couches de filtration profonde.a radial mode in which the layers are in the form of concentric rings traversed laterally from the periphery towards the center or from the center towards the periphery, the storage layer or layers being always traversed before the deep filtration layer or layers.
Le choix d'un mode de fonctionnement en lit axial ou en lit radial est essentiellement lié à l'encombrement du dispositif, mais les performances du dispositif sont les mêmes dans les deux modes.The choice of an operating mode axial bed or radial bed is essentially related to the size of the device, but the performance of the device are the same in both modes.
DESCRIPTION DETAILLEE DE L'INVENTIONDETAILED DESCRIPTION OF THE INVENTION
La présente invention se situe dans le cadre d'un procédé de synthèse d'hydrocarbures à partir d'un mélange gazeux comprenant du monoxyde de carbone et de l'hydrogène, généralement appelé gaz de synthèse, dans un réacteur de type "slurry" au sens précédemment défini. Elle peut néanmoins s'appliquer plus généralement à toute séparation de particules solides de diamètre inférieur à 50 microns, et préférentiellement inférieur à 20 microns, lesdites particules étant en suspension dans une phase liquide hydrocarbonée.The present invention is in the context of a process for the synthesis of hydrocarbons from a gaseous mixture comprising carbon monoxide and hydrogen, generally called synthesis gas, in a "slurry" type reactor in the previously defined sense. It may nevertheless apply more generally to any separation of solid particles with a diameter of less than 50 microns, and preferably less than 20 microns, said particles being suspended in a hydrocarbon liquid phase.
Le réacteur "slurry" dans le cas du procédé Fischer-Tropsch, travaille dans une gamme de température supérieure ou égale à 1500C et généralement comprise entre 1000C et 35O0C, de préférence entre 1700C et 2800C, à une pression généralement comprise entre 0,5 et 20 MPa (1 MPa= 106 pascal), de préférence entre 1 et 10 MPA, de manière plus préférée entre 1 ,5 et 4 MPa, et en présence d'un catalyseur initialement divisé en fines particules de diamètre compris entre 5 et 700 microns, de préférence entre 10 et 500 microns, de manière plus préférée entre 20 et 400 microns. De plus, la granulométrie initiale dudit catalyseur peut évoluer par attrition et le pourcentage de fines particules a alors tendance à augmenter au fil du temps.In the case of the Fischer-Tropsch process, the "slurry" reactor operates in a temperature range greater than or equal to 150 ° C. and generally between 100 ° C. and 35 ° C., preferably between 170 ° C. and 280 ° C., at a pressure generally between 0.5 and 20 MPa (1 MPa = 10 6 pascal), preferably between 1 and 10 MPa, more preferably between 1, 5 and 4 MPa, and in the presence of an initially divided catalyst in fine particles with a diameter of between 5 and 700 microns, preferably between 10 and 500 microns, more preferably between 20 and 400 microns. In addition, the initial particle size of said catalyst can evolve by attrition and the percentage of fine particles then tends to increase over time.
Il est donc important de pouvoir disposer de moyens permettant d'éliminer les particules les plus fines présentes initialement ou formées au cours du temps, c'est-à-dire celles présentant un diamètre inférieur à 100 microns, de préférence inférieur à 80 microns et pouvant dans certains cas présenter des diamètres minima beaucoup plus petits : de l'ordre de quelques microns (1 à 10 microns), voire inférieur au micron.It is therefore important to have means for removing the finest particles present initially or formed over time, that is to say those having a diameter less than 100 microns, preferably less than 80 microns and in some cases may have much smaller minimum diameters: of the order of a few microns (1 to 10 microns), or even less than one micron.
Les catalyseurs Fischer-Tropsch comprennent typiquement du cobalt ou du fer réparti sur un support à base d'au moins un des oxydes des métaux suivants ou de leurs mélanges : silicium (Si), titane (Ti), aluminium (Al), zirconium (Zr) ou magnésium (Mg).Fischer-Tropsch catalysts typically comprise cobalt or iron distributed on a support based on at least one of the following metal oxides or mixtures thereof: silicon (Si), titanium (Ti), aluminum (Al), zirconium ( Zr) or magnesium (Mg).
Un schéma typique d'un procédé de synthèse Fischer-Tropsch fonctionnant en "slurry" est donné sur la figure 1.A typical scheme of a Fischer-Tropsch synthesis process operating in "slurry" is given in FIG.
Le réacteur fluidisé (A) fonctionne en "slurry", avec un échangeur interne comprenant une ou plusieurs boucles de refroidissement (3) alimenté par un fluide (liquide ou vapeur) de refroidissement. La charge gazeuse est introduite dans le réacteur au moyen du distributeur noté (B) et de la ligne (1). Une boucle de recirculation de liquide contenant une partie de gaz est extraite en un point supérieur du réacteur par la ligne (2) et alimente un dégazeur noté (C). Le gaz est éliminé via la ligne (5) et la phase liquide est extraite du dégazeur (C) par la ligne (6), puis introduite dans le système de séparation primaire (E). De ce système de séparation (E), on extrait une première fraction de liquide (7) alimentant le réacteur "slurry" par l'intermédiaire de la pompe (D) et de la ligne (8), et une seconde fraction liquide (9) qui alimente le dispositif de filtration secondaire (F). Par la ligne (10) on recueille un produit liquide répondant aux spécifications de teneur en particules solides.The fluidized reactor (A) operates in "slurry", with an internal exchanger comprising one or more cooling loops (3) supplied by a fluid (liquid or vapor) cooling. The gaseous feed is introduced into the reactor by means of the distributor noted (B) and the line (1). A liquid recirculation loop containing a portion of gas is extracted at an upper point of the reactor by the line (2) and feeds a degasser noted (C). The gas is removed via the line (5) and the liquid phase is extracted from the degasser (C) by the line (6), then introduced into the primary separation system (E). From this separation system (E), a first liquid fraction (7) fed to the "slurry" reactor is extracted via the pump (D) and the line (8), and a second liquid fraction (9). ) which feeds the secondary filtration device (F). By the line (10) is collected a liquid product meeting the specifications of solid content.
Le réacteur "slurry" comprend un système de séparation primaire (E) des particules de catalyseur, qui n'est pas décrit dans la présente demande, mais qui de préférence est, soit de type décanteur, soit un système de cartouches filtrantes. Ce système de séparation primaire peut être soit externe au réacteur, comme indiqué sur figure 1 , soit interne audit réacteur (non représenté).The "slurry" reactor comprises a primary separation system (E) for the catalyst particles, which is not described in the present application, but which is preferably either of decanter type or a system of filter cartridges. This primary separation system may be either external to the reactor, as indicated in FIG. 1, or internal to said reactor (not shown).
Le dispositif de séparation des particules solides est complété par une filtration secondaire (F), objet de la présente invention, qui permet d'abaisser la concentration en particules dans les effluents du réacteur à moins de 10 ppm (partie par million), et préférentiellement à moins de 5 ppm.The device for separating the solid particles is completed by a secondary filtration (F), object of the present invention, which makes it possible to lower the concentration of particles in the effluents of the reactor to less than 10 ppm (parts per million), and preferentially less than 5 ppm.
Les particules solides à séparer dans le système de filtration secondaire sont des fines particules de catalyseur, dont le diamètre est généralement inférieur à 50 microns, et le plus souvent, en fonction des performances de la séparation primaire, inférieur à 20 microns. Ces particules peuvent comporter des particules ultrafines de taille inférieure au micron (particules également appelées submicroniques). La concentration en fines particules à l'entrée du système de filtration secondaire est généralement comprise entre 50 et 500 ppm.The solid particles to be separated in the secondary filtration system are fine catalyst particles, whose diameter is generally less than 50 microns, and most often, depending on the performance of the primary separation, less than 20 microns. These particles may include ultrafine particles smaller than one micron (also called submicron particles). The concentration of fine particles at the inlet of the secondary filtration system is generally between 50 and 500 ppm.
Le dispositif de séparation secondaire est essentiellement constitué d'un lit comportant au moins deux couches de particules distinctes, une première couche destinée à faciliter la formation d'un gâteau, dite aussi couche de stockage, et une seconde couche destinée à piéger en profondeur les fines particules de catalyseur, dite aussi couche de filtration profonde.The secondary separation device essentially consists of a bed comprising at least two distinct particle layers, a first layer intended to facilitate the formation of a cake, also called a storage layer, and a second layer intended to trap in depth the fine particles of catalyst, also called deep filtration layer.
L'appellation "première" et "seconde" couche est à comprendre en fonction du sens d'écoulement du fluide chargé en particules solides. La première couche est traversée par le fluide chargé en particules avant la seconde couche. Sur la figure 2 on a représenté un dispositif de filtration secondaire selon l'invention, fonctionnant en mode axial et alimenté par le liquide chargé en particules par la ligne (6), le liquide déconcentré en particules étant évacué par la ligne (7).The term "first" and "second" layer is to be understood according to the direction of flow of the fluid loaded with solid particles. The first layer is traversed by the particulate-laden fluid before the second layer. FIG. 2 shows a secondary filtration device according to the invention, operating in axial mode and fed by the liquid charged with particles by the line (6), the liquid deconcentrated in particles being evacuated via the line (7).
Le dispositif de filtration secondaire comporte au moins une couche de garde (1), au moins une couche de stockage (2), au moins une couche de filtration profonde (3), et au moins une couche de protection (4) et (5).The secondary filtration device comprises at least one guard layer (1), at least one storage layer (2), at least one deep filtration layer (3), and at least one protective layer (4) and (5) ).
On retrouve ces mêmes couches dans la disposition radiale schématisée sur la figure 3.These same layers are found in the radial arrangement shown schematically in FIG.
Les numéros identiques des figures 2 et 3 désignent les mêmes éléments. La description qui suit vaut donc à la fois pour le dispositif selon l'invention en mode axial (figure 2) ou en mode radial (figure 3).The identical numbers of Figures 2 and 3 designate the same elements. The following description therefore applies to both the device according to the invention in axial mode (FIG. 2) or in radial mode (FIG. 3).
La première couche, ou couche de stockage (2), est généralement constituée de particules macroporeuses inertes, de diamètre compris entre 1 et 3 mm, préférentiellement compris entre 1,5 et 2,5 mm. La porosité moyenne de la couche de stockage est généralement comprise entre 60 % et 75 %, et préférentiellement comprise entre 65 % et 70 % en volume. La surface poreuse offerte par la couche de stockage sera généralement comprise entre 100 et 200 m2/gramme, et préférentiellement comprise entre 150 et 180 m2/gramme.The first layer, or storage layer (2), generally consists of inert macroporous particles with a diameter of between 1 and 3 mm, preferably between 1.5 and 2.5 mm. The average porosity of the storage layer is generally between 60% and 75%, and preferably between 65% and 70% by volume. The porous surface offered by the storage layer will generally be between 100 and 200 m 2 / gram, and preferably between 150 and 180 m 2 / gram.
La seconde couche ou couche de filtration profonde (3) est constituée de particules inertes présentant une distribution de taille comprise entre 0,4 et 80 microns, avec un diamètre moyen compris entre 25 et 35 microns. Ladite couche de filtration profonde présente une distribution de taille de particules telle que 5 % à 20 % du volume de la couche soit représenté par des particules de diamètre inférieur à 4 microns.The second or deep filtration layer (3) consists of inert particles having a size distribution of between 0.4 and 80 microns, with an average diameter of between 25 and 35 microns. Said deep filtration layer has a particle size distribution such that 5% to 20% of the volume of the layer is represented by particles smaller than 4 microns in diameter.
La surface poreuse offerte par la couche de filtration profonde, est généralement comprise entre 100 et 400 m2/gramme, et préférentiellement comprise entre 200 et 300 m2/gramme. Le taux de vide initial de la couche de filtration profonde est généralement compris entre 0,20 et 0,45, et préférentiellement compris entre 0,25 et 0,4. Au cours de la filtration, ce taux de vide diminue en raison des particules solides qui se déposent à l'intérieur de la couche de filtration profonde, entraînant une augmentation de la perte de pression à la traversée du dispositif. En tête et en fond du dispositif de filtration secondaire, il est nécessaire de prévoir une ou plusieurs couches de protection (1), (4) et (5) permettant d'éviter l'entraînement par la phase liquide des particules de la couche de stockage et/ou de la couche de filtration profonde constituant le lit de filtration secondaire.The porous surface offered by the deep filtration layer is generally between 100 and 400 m 2 / gram, and preferably between 200 and 300 m 2 / gram. The initial void ratio of the deep filtration layer is generally between 0.20 and 0.45, and preferably between 0.25 and 0.4. During filtration, this void rate decreases due to the solid particles settling inside the deep filtration layer, causing an increase in the pressure loss at the crossing of the device. At the top and bottom of the secondary filtration device, it is necessary to provide one or more protective layers (1), (4) and (5) to prevent the liquid phase from driving the particles of the filter layer. storage and / or the deep filtration layer constituting the secondary filtration bed.
Ces couches de protection ou de garde ne sont pas des éléments distinctifs de la présente invention, et peuvent être de tout type connu de l'homme du métier. Le lit de filtration secondaire est généralement opéré à une température comprise entre 13O0C et 2500C, et préférentiellement comprise entre 150°C et 23O0C.These protective or guard layers are not distinctive elements of the present invention, and may be of any type known to those skilled in the art. The secondary filtration bed is generally operated at a temperature of between 130 ° C. and 250 ° C., and preferably between 150 ° C. and 23 ° C.
La vitesse superficielle du fluide chargé en fines particules à l'intérieur du lit de filtration est généralement comprise entre 0,3 mètre/heure et 1 mètre/heure. La vitesse superficielle est définie comme le rapport du débit volumique de charge sur la section vide du lit de filtration.The superficial velocity of the fluid charged in fine particles inside the filtration bed is generally between 0.3 meters / hour and 1 meter / hour. The superficial velocity is defined as the ratio of the volume flow rate of charge to the empty section of the filtration bed.
L'épaisseur de la couche de stockage est de préférence comprise entre 0,3 mètre et 2 mètres, et plus préférentiellement entre 0,5 mètre et 1,0 mètre. L'épaisseur de la couche de filtration profonde est de préférence comprise entre 0,1 mètre et 2 mètres, et préférentiellement entre 0,2 mètre et 1,5 mètres.The thickness of the storage layer is preferably between 0.3 meters and 2 meters, and more preferably between 0.5 meters and 1.0 meters. The thickness of the deep filtration layer is preferably between 0.1 meters and 2 meters, and preferably between 0.2 meters and 1.5 meters.
Le dispositif de filtration selon l'invention peut éventuellement contenir plusieurs couches de stockage et plusieurs couches de filtration profonde, une couche de stockage ayant de préférence au moins une épaisseur de 0,3 mètre, et une couche de filtration profonde ayant de préférence au moins une épaisseur de 0,1 mètre.The filtration device according to the invention may optionally contain several storage layers and several deep filtration layers, a storage layer preferably having at least a thickness of 0.3 meters, and a deep filtration layer preferably having at least a thickness of 0.1 meters.
La limite en épaisseur du lit de filtration secondaire est conditionnée par la perte de pression, qui doit rester inférieure à une valeur limite dépendant de la puissance des pompes installées. Afin de réduire les coûts de fonctionnement, la perte de pression est maintenue sous 0,1 MPa, préférentiellement sous 0,05 MPa en fin de filtration.The thickness limit of the secondary filtration bed is conditioned by the pressure loss, which must remain below a limit value depending on the power of the pumps installed. In order to reduce operating costs, the pressure loss is maintained at 0.1 MPa, preferably at 0.05 MPa at the end of filtration.
La perte de pression augmente avec la rétention en fines particules. Lorsqu'elle atteint la valeur limite décrite précédemment, le filtre est arrêté pour être vidé soit par gravité, soit par aspiration par le haut. L'intégralité des couches doit être remplacé avant remise en route du filtre. Un des avantages de l'invention est que, si la charge évolue, et avec elle les caractéristiques des particules à filtrer, il est très aisé de moduler les épaisseurs et/ou le type de média de filtration utilisé pour optimiser la filtration aux nouvelles conditions.The loss of pressure increases with retention in fine particles. When it reaches the limit value described above, the filter is stopped to be emptied either by gravity or by suction from above. All layers must be replaced before restarting the filter. One of the advantages of the invention is that, if the charge evolves, and with it the characteristics of the particles to be filtered, it is very easy to modulate the thicknesses and / or the type of filtration media used to optimize filtration under the new conditions.
La durée typique de fonctionnement du système de filtration secondaire selon l'invention est au moins de 5 jours, et préférentiellement d'au moins 10 jours.The typical operating time of the secondary filtration system according to the invention is at least 5 days, and preferably at least 10 days.
EXEMPLESEXAMPLES
Les deux exemples ci-dessous fournissent les dimensions principales d'un système de séparation secondaire selon l'invention en mode de lit axial (exemple 1) et en mode de lit radial (exemple 2).The two examples below provide the main dimensions of a secondary separation system according to the invention in axial bed mode (example 1) and in radial bed mode (example 2).
L'unité de synthèse Fischer-Tropsch dans laquelle le dispositif de filtration secondaire selon l'invention s'incorpore, comporte un réacteur "slurry" de type S B C (colonne à bulles avec un catalyseur en suspension ou "Slurry Bubble Column", selon la terminologie anglosaxonne) traitant 30 tonnes/heure d'une charge de gaz de synthèse aux conditions opératoires suivantes :The Fischer-Tropsch synthesis unit in which the secondary filtration device according to the invention is incorporated, comprises a slurry reactor of the SBC type (bubble column with a suspension catalyst or "Slurry Bubble Column", according to the anglosaxon terminology) treating 30 tonnes / hour of a syngas charge under the following operating conditions:
Température : 2200CTemperature: 220 0 C
Pression : 2,5 MPa.Pressure: 2.5 MPa.
Le catalyseur utilisé est à base de cobalt, et les particules en suspension ont un diamètre moyen de 150 microns, dont 300 ppm ont un diamètre inférieur à 25 microns.The catalyst used is based on cobalt, and the particles in suspension have an average diameter of 150 microns, 300 ppm of which have a diameter of less than 25 microns.
Le système de filtration primaire est constitué d'un ensemble de cartouches de filtration du type commercial PALL de type "Rigimesh K".The primary filtration system consists of a set of filtration cartridges of commercial type PALL type "Rigimesh K".
Exemple 1 (selon l'invention, figure 2)Example 1 (according to the invention, FIG. 2)
En mode axial, le dispositif de filtration secondaire est constitué par 4 lits de filtration en parallèle dont un est déconnecté pour permettre son déchargement. Chaque lit de filtration a un diamètre de 5,3 mètres, et comporte les 6 couches suivantes de haut en bas :In axial mode, the secondary filtration device consists of 4 parallel filtration beds, one of which is disconnected to allow unloading. Each filter bed has a diameter of 5.3 meters, and has the following 6 layers from top to bottom:
1) une couche de garde (1) d'une hauteur de 0,1 m, constituée de billes d'alumine inerte de % de pouce,1) a guard layer (1) of a height of 0.1 m, consisting of inert alumina balls of% inch,
2) une couche de stockage (2) d'une hauteur de 1,5 m, constituée de particules de billes d'alumine de 2 mm de type SCM139XL, 3) une couche de filtration profonde (3) d'une hauteur de 1,2 mètre, constituée de particules de diamètre compris entre 20 microns et 30 microns de type GA3001 ,2) a storage layer (2) with a height of 1.5 m, consisting of SCM139XL-type particles of 2 mm alumina beads, 3) a deep filtration layer (3) with a height of 1.2 meters, consisting of particles of diameter between 20 microns and 30 microns of GA3001 type,
4) une couche de sable (4) de diamètre compris entre 40 microns et 315 microns,4) a sand layer (4) of diameter between 40 microns and 315 microns,
5) une couche de sable de diamètre compris entre 400 microns et 1 000 microns (non représentée sur la figure 2),5) a sand layer with a diameter of between 400 microns and 1000 microns (not shown in FIG. 2),
6) une couche de billes d'aluminium de diamètre compris entre 2 mm et 3 mm (non représentée sur la figure 2),6) a layer of aluminum balls having a diameter of between 2 mm and 3 mm (not shown in FIG. 2),
7) une grille de retenue (5) de type "Johnson" (ou équivalent).7) a retaining grid (5) of type "Johnson" (or equivalent).
La durée de cycle d'un lit, c'est-à-dire sa durée de fonctionnement avant sa déconnection est de 63 jours. La teneur en particules en sortie de la filtration secondaire est inférieure à 5 ppm et l'effluent est totalement blanc.The cycle time of a bed, that is to say its operating time before disconnection is 63 days. The content of particles at the outlet of the secondary filtration is less than 5 ppm and the effluent is totally white.
Exemple 2 (selon l'invention, figure 3)Example 2 (according to the invention, FIG. 3)
En mode radial, le dispositif de filtration secondaire est constitué de deux lits radiaux, dont l'un est en situation de déchargement. Chaque lit radial est composé de couches cylindriques coaxiales. Le diamètre extérieur d'un lit est de 6,4 mètres et sa hauteur total est de 8,7 mètres.In radial mode, the secondary filtration device consists of two radial beds, one of which is in an unloading situation. Each radial bed is composed of coaxial cylindrical layers. The outside diameter of a bed is 6.4 meters and its total height is 8.7 meters.
De l'extérieur vers l'intérieur, le fluide chargé en particules solides traverse les couches suivantes :From the outside to the inside, the fluid charged with solid particles passes through the following layers:
1 ) une couche de garde (1 ) d'épaisseur 0, 1 mètre,1) a guard layer (1) with a thickness of 0.1 meters,
2) une couche de stockage (2) d'épaisseur à 0,5 mètre, constituée de particules de billes d'alumines de 2mm de type SCM 139XL,2) a storage layer (2) with a thickness of 0.5 meters, consisting of particles of SCM 139XL 2mm alumina balls,
3) une couche de filtration profonde (3) d'épaisseur 1,2 mètres, constituée de particules d'alumine de diamètre compris entre 20 et 30 microns de type GA.3001 ,3) a deep filtration layer (3) 1.2 meters thick, consisting of alumina particles with a diameter of between 20 and 30 microns of GA.3001 type,
4) une couche de garde (4) composée de particules de diamètre compris entre 60 et 500 microns,4) a guard layer (4) composed of particles of diameter between 60 and 500 microns,
5) une grille de rétention de type Johnson ou équivalent (5).5) a Johnson type retention grid or equivalent (5).
La durée de fonctionnement d'un lit est de 62 jours. La teneur en particules en sortie de la filtration secondaire est inférieure à 5 ppm et l'effluent est totalement blanc.The operating time of a bed is 62 days. The content of particles at the outlet of the secondary filtration is less than 5 ppm and the effluent is totally white.
Les particules en quantité très réduite encore présentes dans l'effluent de la filtration secondaire ont un diamètre inférieur à 0,2 micron, de sorte que l'effluent liquide après refroidissement, constitué essentiellement de paraffines, est totalement blanc. Or, dès que l'effluent contient au moins 10 ppm de particules, il devient habituellement gris. Le test visuel est donc parfaitement discriminant et confirme la faible teneur en particules de l'effluent. The particles in a very small quantity still present in the filtration effluent secondary have a diameter less than 0.2 micron, so that the liquid effluent after cooling, consisting essentially of paraffins, is completely white. However, as soon as the effluent contains at least 10 ppm of particles, it usually becomes gray. The visual test is therefore perfectly discriminating and confirms the low particulate content of the effluent.

Claims

REVENDICATIONS
1. Dispositif de séparation secondaire de particules solides de diamètre inférieur à 50 microns, et préférentiellement inférieur à 20 microns, en suspension dans une phase liquide hydrocarbonée, placé en aval d'un dispositif de séparation primaire de ladite phase liquide hydrocarbonée chargée en particules solides, comportant au moins deux couches :1. Device for secondary separation of solid particles with a diameter of less than 50 microns, and preferably less than 20 microns, in suspension in a hydrocarbon liquid phase, placed downstream of a primary separation device of said hydrocarbon liquid phase loaded with solid particles , having at least two layers:
- une première couche dite de stockage, constituée de particules macro poreuses inertes, de diamètre compris entre 1 mm et 3 mm et,a first so-called storage layer consisting of inert macro porous particles with a diameter of between 1 mm and 3 mm and
- une seconde couche dite de filtration profonde, constituée de particules inertes présentant une distribution de taille comprise entre 0,4 et 80 microns, avec un diamètre moyen compris entre 25 et 35 microns, et dans lequel ledit dispositif présente un mode de fonctionnement en lit axial ou en lit radial .a second so-called deep filtration layer, consisting of inert particles having a size distribution of between 0.4 and 80 microns, with an average diameter of between 25 and 35 microns, and in which said device exhibits a mode of operation in a bed axial or radial bed.
2. Dispositif selon la revendication 1 dans lequel la première couche dite de stockage est constituée de particules présentant un diamètre compris entre 1 ,5 mm et 2,5 mm.2. Device according to claim 1 wherein the first so-called storage layer consists of particles having a diameter of between 1.5 mm and 2.5 mm.
3. Dispositif de séparation secondaire selon l'une des revendications 1 et 2 dans lequel la distribution de taille de particules de la couche de filtration profonde est telle que 5 % à 20 % du volume de la couche est représenté par des particules de diamètre inférieur à 4 microns.3. secondary separation device according to one of claims 1 and 2 wherein the particle size distribution of the deep filtration layer is such that 5% to 20% of the volume of the layer is represented by particles of smaller diameter at 4 microns.
4. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 3 dans lequel ledit dispositif contient plusieurs couches de stockage et plusieurs couches de filtration profonde.4. secondary separation device according to any one of claims 1 to 3 wherein said device contains several storage layers and several deep filtration layers.
5. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 4, dans lequel la porosité moyenne de la ou des couches de stockage est comprise entre 60 % et 75 %.5. secondary separation device according to any one of claims 1 to 4, wherein the average porosity of the storage layer or layers is between 60% and 75%.
6. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 5, dans lequel la surface poreuse de la ou des couches de stockage est comprise entre 100 et 200 m2/gramme.6. secondary separation device according to any one of claims 1 to 5, wherein the porous surface of the storage layer or layers is between 100 and 200 m 2 / gram.
7. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 6, dans lequel l'épaisseur totale de la ou des couches de stockage est comprise entre 0,3 mètre et 2 mètres, et préférentiellement comprise entre 0,5 mètre et 1 mètre.7. secondary separation device according to any one of claims 1 to 6, wherein the total thickness of the storage layer or layers is between 0.3 meters and 2 meters, and preferably between 0.5 meters and 1 meter.
8. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 7, dans lequel le taux de vide initial de la ou des couches de filtration profonde est compris entre 0,2 et 0,45.8. secondary separation device according to any one of claims 1 to 7, wherein the initial vacuum rate of the deep filtration layer or layers is between 0.2 and 0.45.
9. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 8, dans lequel l'épaisseur totale de la ou des couches de filtration profonde est comprise entre 0,1 mètre et 2 mètres.9. secondary separation device according to any one of claims 1 to 8, wherein the total thickness of the deep filtration layer or layers is between 0.1 meter and 2 meters.
10. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 9, dans lequel le système de filtration secondaire fonctionne en lit axial.10. Secondary separation device according to any one of claims 1 to 9, wherein the secondary filtration system operates in axial bed.
11. Dispositif de séparation secondaire selon l'une quelconque des revendications 1 à 9, dans lequel le système de filtration secondaire fonctionne en lit radial.11. secondary separation device according to any one of claims 1 to 9, wherein the secondary filtration system operates in a radial bed.
12. Procédé de séparation secondaire mettant en oeuvre le dispositif selon l'une des revendications 1 à 11.12. Secondary separation process using the device according to one of claims 1 to 11.
13. Procédé de séparation de particules de catalyseurs de synthèse d'hydrocarbures Fischer-Tropsch mettant en oeuvre le dispositif selon l'une des revendications 1 à 11. 13. Process for separating Fischer-Tropsch hydrocarbon synthesis catalyst particles using the device according to one of claims 1 to 11.
PCT/FR2006/002648 2005-12-20 2006-12-01 Secondary filtration device applicable to a three-phase process WO2007080247A1 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
CN2006800480873A CN101410161B (en) 2005-12-20 2006-12-01 Secondary filtration device applicable to a three-phase process
DE602006009558T DE602006009558D1 (en) 2005-12-20 2006-12-01 SECONDARY FILTRATION DEVICE USED IN A THREE-PHASE PROCESS
PL06841856T PL1965885T3 (en) 2005-12-20 2006-12-01 Secondary filtration device applicable to a three-phase process
EP06841856A EP1965885B1 (en) 2005-12-20 2006-12-01 Secondary filtration device applicable to a three-phase process
AT06841856T ATE444113T1 (en) 2005-12-20 2006-12-01 SECONDARY FILTERING DEVICE USABLE IN A THREE-PHASE PROCESS
US12/158,428 US8092694B2 (en) 2005-12-20 2006-12-01 Secondary filtration device applicable to a three-phase process
NO20082392A NO344338B1 (en) 2005-12-20 2008-05-27 Secondary filtration device usable for a three-phase process
EG2008050890A EG25597A (en) 2005-12-20 2008-05-28 Secondary filtration device applicable to a three-phase process

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0513207A FR2894840B1 (en) 2005-12-20 2005-12-20 SECONDARY FILTRATION DEVICE APPLICABLE TO A THREE PHASE PROCESS
FR0513207 2005-12-20

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EP (1) EP1965885B1 (en)
CN (1) CN101410161B (en)
AT (1) ATE444113T1 (en)
DE (1) DE602006009558D1 (en)
EG (1) EG25597A (en)
FR (1) FR2894840B1 (en)
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PL (1) PL1965885T3 (en)
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US20020128330A1 (en) * 2001-03-12 2002-09-12 Texaco Inc. Internal filter for fischer-tropsch catalyst/wax separation

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US5527473A (en) * 1993-07-15 1996-06-18 Ackerman; Carl D. Process for performing reactions in a liquid-solid catalyst slurry
US6488842B2 (en) * 1999-02-26 2002-12-03 Tadayoshi Nagaoka Filtering device
CN1233453C (en) * 2003-09-03 2005-12-28 上海兖矿能源科技研发有限公司 Automatic filtering/back purging system liquid and solid separation for in three phase paste state bed reactor

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Publication number Priority date Publication date Assignee Title
US1838263A (en) * 1931-02-21 1931-12-29 Kelley Engineering Company Filter for purifying cleaning solvents, gasoline, etc.
US1992420A (en) * 1932-06-13 1935-02-26 Standard Oil Co Method and apparatus for treating oils
US3382983A (en) * 1964-03-16 1968-05-14 Dixie Entpr Inc Multi-layered filter apparatus
US4591437A (en) * 1982-06-04 1986-05-27 Leif Ernryd Ab Apparatus for separating solid particles from a liquid
EP0925818A1 (en) * 1997-12-22 1999-06-30 Aaf International Apparatus and method for maximizing filtering capacity of layered filter media
US20020128330A1 (en) * 2001-03-12 2002-09-12 Texaco Inc. Internal filter for fischer-tropsch catalyst/wax separation

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US8092694B2 (en) 2012-01-10
EP1965885A1 (en) 2008-09-10
CN101410161B (en) 2012-07-04
ATE444113T1 (en) 2009-10-15
DE602006009558D1 (en) 2009-11-12
NO344338B1 (en) 2019-11-04
CN101410161A (en) 2009-04-15
NO20082392L (en) 2008-06-23
EG25597A (en) 2012-03-18
ZA200804487B (en) 2009-03-25
PL1965885T3 (en) 2010-05-31
FR2894840B1 (en) 2008-05-30
US20090008305A1 (en) 2009-01-08
EP1965885B1 (en) 2009-09-30
FR2894840A1 (en) 2007-06-22

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